2 * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file send_common.c Functions used by more than one paraslash sender. */
23 #include "close_on_fork.h"
24 #include "chunk_queue.h"
28 /** Clients will be kicked if there are more than that many bytes pending. */
29 #define MAX_CQ_BYTES 40000
32 * Open a passive socket of given layer4 type.
34 * Set the resulting file descriptor to nonblocking mode and add it to the list
35 * of fds that are being closed in the child process when the server calls
38 * \param l4type The transport-layer protocol.
39 * \param port The port number.
41 * \return The listening fd on success, negative on errors.
43 static int open_sender(unsigned l4type, int port)
45 int fd, ret = para_listen_simple(l4type, port);
50 ret = mark_fd_nonblocking(fd);
55 add_close_on_fork_list(fd);
60 * Shut down a client connected to a paraslash sender.
62 * \param sc The client to shut down.
63 * \param ss The sender whose clients are to be shut down.
65 * Close the file descriptor given by \a sc, remove it from the close-on-fork
66 * list, destroy the chunk queue of this client, delete the client from the
67 * list of connected clients and free the sender_client struct.
69 * \sa shutdown_clients().
71 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
73 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
76 del_close_on_fork_list(sc->fd);
79 free(sc->private_data);
85 * Shut down all clients connected to a paraslash sender.
87 * \param ss The sender whose clients are to be shut down.
89 * This just loops over all connected clients and calls shutdown_client()
92 void shutdown_clients(struct sender_status *ss)
94 struct sender_client *sc, *tmp;
95 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
96 shutdown_client(sc, ss);
100 * Try to empty the chunk queue for this fd.
102 * \param fd The file descriptor.
103 * \param cq The list of queued chunks.
105 * \return Negative on errors, zero if not everything was sent, one otherwise.
107 int send_queued_chunks(int fd, struct chunk_queue *cq)
109 struct queued_chunk *qc;
110 while ((qc = cq_peek(cq))) {
115 cq_get(qc, &buf, &len);
116 ret = xwrite(fd, buf, len);
128 * Initialize a struct sender status.
130 * \param ss The struct to initialize.
131 * \param access_arg The array of access arguments given at the command line.
132 * \param num_access_args The number of elements in \a access_arg.
133 * \param port The tcp or dccp port to listen on.
134 * \param max_clients The maximal number of simultaneous connections.
135 * \param default_deny Whether a blacklist should be used for access control.
137 void init_sender_status(struct sender_status *ss, char **access_arg,
138 int num_access_args, int port, int max_clients, int default_deny)
141 INIT_LIST_HEAD(&ss->client_list);
143 acl_init(&ss->acl, access_arg, num_access_args);
145 ss->max_clients = max_clients;
146 ss->default_deny = default_deny;
150 * Return a string containing the current status of a sender.
152 * \param ss The sender.
153 * \param name Used for printing the header line.
155 * \return The string printed in the "si" command.
157 char *get_sender_info(struct sender_status *ss, const char *name)
159 char *clnts = NULL, *ret;
160 struct sender_client *sc, *tmp_sc;
162 char *acl_contents = acl_get_contents(&ss->acl);
163 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
164 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
172 "\tnumber of connected clients: %d\n"
173 "\tmaximal number of clients: %d%s\n"
174 "\tconnected clients: %s\n"
175 "\taccess %s list: %s\n",
177 (ss->listen_fd >= 0)? "on" : "off",
178 stringify_port(ss->port, strcmp(name, "http") ? "dccp" : "tcp"),
181 ss->max_clients > 0? "" : " (unlimited)",
182 clnts? clnts : "(none)",
183 ss->default_deny? "allow" : "deny",
184 acl_contents? acl_contents : "(empty)"
192 * Allow connections from the given range of IP addresses.
194 * \param scd Contains the IP and the netmask.
195 * \param ss The sender.
197 * \sa generic_com_deny().
199 void generic_com_allow(struct sender_command_data *scd,
200 struct sender_status *ss)
202 acl_allow(scd->host, scd->netmask, &ss->acl, ss->default_deny);
206 * Deny connections from the given range of IP addresses.
208 * \param scd see \ref generic_com_allow().
209 * \param ss see \ref generic_com_allow().
211 * \sa generic_com_allow().
213 void generic_com_deny(struct sender_command_data *scd,
214 struct sender_status *ss)
216 acl_deny(scd->host, scd->netmask, &ss->acl, ss->default_deny);
220 * Activate a paraslash sender.
222 * \param ss The sender to activate.
223 * \param protocol The symbolic name of the transport-layer protocol.
227 int generic_com_on(struct sender_status *ss, unsigned protocol)
231 if (ss->listen_fd >= 0)
233 ret = open_sender(protocol, ss->port);
241 * Deactivate a paraslash sender.
243 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
245 * \param ss The sender to deactivate.
247 * \sa \ref del_close_on_fork_list(), shutdown_clients().
249 void generic_com_off(struct sender_status *ss)
251 if (ss->listen_fd < 0)
253 PARA_NOTICE_LOG("closing port %d\n", ss->port);
254 close(ss->listen_fd);
255 del_close_on_fork_list(ss->listen_fd);
256 shutdown_clients(ss);
261 * Accept a connection on the socket this server is listening on.
263 * \param ss The sender whose listening fd is ready for reading.
264 * \param rfds Passed to para_accept(),
266 * This must be called only if the socket fd of \a ss is ready for reading. It
267 * calls para_accept() to accept the connection and performs the following
268 * actions on the resulting file descriptor \a fd:
270 * - Checks whether the maximal number of connections are exceeded.
271 * - Sets \a fd to nonblocking mode.
272 * - Checks the acl of the sender to find out whether connections
273 * are allowed from the IP of the connecting peer.
274 * - Increases the number of connections for this sender.
275 * - Creates and initializes a new chunk queue for queuing network
276 * packets that can not be sent immediately.
277 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
278 * and \a name members.
279 * - Adds \a fd to the list of connected clients for this sender.
280 * - Adds \a fd to the list of file descriptors that should be closed
281 * in the child process when the server calls fork().
283 * \return A pointer to the allocated sender_client structure on success, \p
286 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
287 * \ref cq_new(), \ref add_close_on_fork_list().
289 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds)
291 struct sender_client *sc;
294 if (ss->listen_fd < 0)
296 ret = para_accept(ss->listen_fd, rfds, NULL, 0, &fd);
298 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
301 ret = -E_MAX_CLIENTS;
302 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
304 ret = mark_fd_nonblocking(fd);
307 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
311 sc = para_calloc(sizeof(*sc));
313 sc->name = para_strdup(remote_name(fd));
314 sc->cq = cq_new(MAX_CQ_BYTES);
315 para_list_add(&sc->node, &ss->client_list);
316 add_close_on_fork_list(fd);
317 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
321 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
327 * Get the generic help text.
329 * \return A dynamically allocated string containing the help text for
330 * a paraslash sender.
332 char *generic_sender_help(void)
336 "usage: {allow|deny} IP[/netmask]\n"
337 " where mask defaults to 32\n"
338 "example: allow 192.168.0.1/24\n"
342 static int parse_fec_parms(const char *arg, struct sender_command_data *scd)
345 char *a = para_strdup(arg),
347 *c = strrchr(a, ':');
348 int ret = -E_COMMAND_SYNTAX;
354 ret = para_atoi32(a, &val);
358 /* optional max_slice_bytes (0 means "use MTU") */
360 scd->max_slice_bytes = 0;
362 if (val < 0 || val > 65535)
364 scd->max_slice_bytes = val;
366 ret = para_atoi32(b + 1, &val);
371 /* k = data_slices_per_group */
372 if (val < 0 || val > 255)
374 scd->data_slices_per_group = val;
376 /* n = slices_per_group */
377 ret = para_atoi32(c + 1, &val);
380 if (val < 0 || val < scd->data_slices_per_group)
382 scd->slices_per_group = val;
388 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
393 * Parse a FEC URL string.
395 * \param arg the URL string to parse.
396 * \param scd The structure containing host, port and the FEC parameters.
400 * A FEC URL consists of an ordinary URL string according to RFC 3986,
401 * optionally followed by a slash and the three FEC parameters slice_size,
402 * data_slices_per_group and slices_per_group. The three FEC parameters are
403 * separated by colons.
405 * \sa \ref parse_url().
407 int parse_fec_url(const char *arg, struct sender_command_data *scd)
409 char *a = para_strdup(arg), *p = strchr(a, '/');
412 /* default fec parameters */
413 scd->max_slice_bytes = 0;
414 scd->data_slices_per_group = 14;
415 scd->slices_per_group = 16;
419 ret = parse_fec_parms(p + 1, scd);
423 if (!parse_url(a, scd->host, sizeof(scd->host), &scd->port))
424 ret = -ERRNO_TO_PARA_ERROR(EINVAL);